                (a) Field of the Invention        
The invention relates to a die-casting device, and more particularly, to a lower mold mechanism of an upright die-casting device. The lower mold mechanism is devised as being inclined with an appropriate angle, such that when a metal liquid is filled into a material reservoir at an upper section of an injection mechanism, a flow speed thereof is reduced to avoid formation of bubbles, thereby preventing finished die-casting products from containing bubbles and thus elevating product quality.
(b) Description of the Prior Art
A prior die-casting device comprises at least a lower mold mechanism at a seat of a machine body thereof. The lower mold mechanism has a lower section thereof joined with an oil-pressured injection mechanism, and the machine body has an upper section thereof provided with a corresponding upper mold mechanism driven by an oil-pressured mechanism for up-and-down movements. When the lower mold mechanism is filled with a metal liquid, the upper mold mechanism is descended to correspond and seal with the lower mold mechanism, followed by the injection mechanism pressing the aforesaid metal liquid into a mold chamber between the upper and lower mold mechanisms to complete die-casting.
However, during a process of adding a metal liquid of zinc, tin, aluminum or copper for die-casting using the aforesaid prior die-casting device, for that the lower mold mechanism of the prior die-casting device is an immobile and upright structure, the metal liquid is rapidly and vertically rushed into a material reservoir at an upper end of the injection mechanism when a metal liquid device pours the metal liquid through a cast opening of the lower mold mechanism. As a result, bubbles in the metal liquid in the material reservoir are frequently produced. These bubbles are aluminum oxides commonly referred to as dregs. Similar to pouring water, when the poured water comes to direct impact with a surface of the water, numerous bubbles are formed in the water. However, such phenomenon is quickly disappeared in water, whereas in a liquid having little fluidity and high cohesion, it is rather difficult to totally eliminate bubbles contained in the metal liquid that is filled into the mold chamber and takes formation in an extremely short period before the metal liquid solidifies. Thus, many bubbles are often remained in finished die-casting products using the prior die-casting device. Strength and appearance quality of such products are affected to reduce competitiveness and economical values of these products on market. It is essential that the prior die-casting device be advanced.